| 1. |
- Aldaeus, Fredrik, et al.
(författare)
-
Characterization of pulp with high enzymatic hydrolyzability
- 2014
-
Ingår i: 13th European Workshop on Lignocellulosics and Pulp (EWLP 2014) book of abstracts.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Conversion of biomass to biofuels is currently an area that attracts large interest, and lignocellulosic biomass offers the abundance and environmental attributes that can potentially support large-scale biofuel production as an alternative to petroleum-based transportation fuel.In a recent project, Innventia has developed wood based pulps optimized for conversion to biofuels. These novel pulps were produced to target a high level of enzymatic hydrolyzability. To assess the hydrolyzability of these pulps, a laboratory protocol has been established usingan enzyme mixture containing Celluclast 1.5L and Novozyme 188 with an activity of 10 FPU/g pulp (Andersen 2007). Results obtained using this protocol are assumed to be relevant for industrial conditions. In addition to assessment of the produced pulps, the results havebeen compared to commercial cellulose substrates and pulps of a variety of grades.Furthermore, supramolecular properties – specific surface area and average pore size – were determined by an in-house method utilizing solid state nuclear magnetic resonance (Larsson et al. 2013). Kappa numbers, limiting viscosities, ISO-brightness and carbohydrate compositions were determined using standard methods. Molecular mass distributions of cellulose tricarbanilates were determined by size exclusion chromatography with tetrahydrofuran mobile phase (Drechsler et al. 2000).The presentation will discuss the influence of chemical, macromolecular and supramolecular properties of commercial and novel pulp grades on the enzymatic hydrolyzability. Theprotocol used to assess of enzymatic hydrolyzability will be proposed as a benchmark test.
|
|
| 2. |
|
|
| 3. |
- Aldaeus, Fredrik, et al.
(författare)
-
The supramolecular structure of cellulose-rich wood and wheat straw pulps can be a determinative factor for enzymatic hydrolysability
- 2016
-
Ingår i: The 7th Workshop on cellulose, regenerated cellulose and cellulose derivatives. ; , s. 39-39
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Conversion of biomass to biofuels and other products is a research area that is currently attracting a great amount of interest, particularly because such production may be envisaged as a key part of any bio-based economy. Lignocellulosic biomass is abundant and sustainable, and can therefore potentially support large-scale production of biofuel as an alternative to petroleum-based fuel.The enzymatic hydrolysability of three industrial pulps, five lab made pulps, and one microcrystalline cellulose powder was assessed using commercial cellulolytic enzymes. To gain insight into the factors that influence the hydrolysability, a thorough characterization of the samples was done, including their chemical properties (cellulose content, hemicellulose content, lignin content, and kappa number), their macromolecular properties (peak molar mass, number-average molar mass, weight-average molar mass, polydispersity, and limiting viscosity) and their supramolecular properties (fibre saturation point, specific surface area, average pore size, and crystallinity). The hydrolysability was assessed by determination of initial conversion rate and final conversion yield, with conversion yield defined as the amount of glucose in solution per unit of glucose in the substrate. Multivariate data analysis revealed that for the investigated samples the conversion of cellulose to glucose was mainly dependent on the supramolecular properties, such as specific surface area and average pore size. The molar mass distribution, the crystallinity, and the lignin content of the pulps had no significant effect on the hydrolysability of the investigated samples.In addition, experiments were carried out aiming at identifying suitable conditions for pre-treatment of wheat straw, for the purpose of making cellulose rich pulps with improved enzymatic reactivity. Two sets of conditions for pre-treatment of wheat straw were identified; a combination of low temperature alkaline washing and acid pre-hydrolysis, or high temperature acid pre-hydrolysis. Both bleached wheat straw pulps showed similar enzymatic reactivity. However, the enzymatic reactivity of both bleached wheat straw pulps was found to be significantly less than what has been achieved for wood pulps. A probable explanation for the low enzymatic reactivity of the bleached wheat straw pulp can be the small pore size, limiting the access for enzymes to the cellulose surfaces in the fibre wall interior.Text, figures and tables in an extended abstract (< 4 pages with title and references).
|
|
| 4. |
- Alm, Hajer Kamal, et al.
(författare)
-
Effect of excess dispersant on surface properties and liquid interactions on calcium carbonate containing coatings
- 2010
-
Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 25:1, s. 82-92
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this work was to identify what effects excess amount of sodium polyacrylate, a commonly used dispersant, has on the coating properties and the interaction between ink and the paper coating in offset printing. Since polyacrylate strongly interacts with calcium ions, soluble calcium salt was added to some coating colours to illustrate the impact of charge neutralization by calcium ions. It was found that the coating structure was only slightly affected by the extra addition of polyacrylate, showing some weak flocculation, whereas the surface chemistry was strongly influenced. The coatings became more polar and interacted more strongly with water. This resulted in slower ink setting and reduced ink-paper coating adhesion, especially in the presence of applied water/dampening solution, which are identified as contributory factors in ink piling and print mottle.
|
|
| 5. |
- Antonsson, Stefan, et al.
(författare)
-
Applying a novel cooking technique to produce high kappa number pulps : the effects on physical properties
- 2009
-
Ingår i: Nordic Pulp & Paper Research Journal. - : Walter de Gruyter GmbH. - 0283-2631 .- 2000-0669. ; 24:4, s. 415-420
-
Tidskriftsartikel (refereegranskat)abstract
- A recently developed kraft cooking technique, with a longer impregnation time at lower temperatures to facilitate diffusion over consumption of active cooking chemicals, makes it possible to produce kraftliner pulp without inline refining. This technique was applied to prepare two pulps with different lignin contents, which were compared with two industrial pulps from conventional kraft cooks in order to evaluate the physical properties of the pulps. It was demonstrated that pulps with lower lignin content can increase tensile stiffness, decrease hygroexpansion, and decrease the mechano-sorptive creep of handsheets. However, no difference in SCT and tensile energy absorption values due to different lignin contents was observed. It was further demonstrated that pulps made with Extended Impregnation Cooking (EIC) results in straighter pulp fibres with higher cellulose content. These pulps tended to have lower mechano-sorptive creep than conventional pulps. A higher brightness of the pulp sheets can also be obtained by choosing a higher alkali profile.
|
|
| 6. |
- Antonsson, Stefan, et al.
(författare)
-
The relationship between hygroexpansion, tensile stiffness, and mechano–sorptive creep in bleached hardwood kraft pulps
- 2010
-
Ingår i: Appita journal. - 1038-6807. ; 63:1, s. 231-
-
Tidskriftsartikel (refereegranskat)abstract
- Hygroexpansion coefficient and tensile stiffness are important parameters in many paper applications. This study compares several bleached industrial hardwood kraft pulps, comprising five eucalypt pulps from South America, Europe, and Africa as well as an acacia pulp from Asia and a birch pulp from Scandinavia. Refined and unrefined pulps are compared. The results indicate significant differences in hygroexpansion but smaller differences in tensile stiffness index at comparable densities. No single factor offering a reasonable explanation of these differences in hygroexpansion coefficient, such as carbohydrate composition, fibre dimensions, or fibre form, was found. However, correlation between hygroexpansion coefficient and the mechano-sorptive creep stiffness was observed. We suggest that the hygroexpansion coefficient at a given tensile stiffness level can be used to rank pulps in terms of their mechano-sorptive creep properties.
|
|
| 7. |
- Bäck, Lena, 1962-
(författare)
-
Confidence in Midwifery : Midwifery students and midwives’ perspectives
- 2018
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A confident midwife has an impact on a pregnant woman’s clinical outcome and birth experience. Knowledge acquisition, competence, and confidence develops over a lifetime and is of great importance in developing and forming personal skills and allowing the personal traits to grow and mature. Previous international studies have shown that midwifery students do not feel confident in many areas in which they are supposed to practice independently. The aim of this thesis was to investigate confidence levels in basic midwifery skills in Swedish midwifery students in their final semester just before entering the midwifery profession. An additional aim was to describe clinical midwives’ reflections about learning and what factors that developes professional competence, and confidence.Study I was a cross-sectional survey with Swedish midwifery students (n=238). They assessed their own confidence in all competencies that a midwife should have and could practice independently. The results of study I confirmed that Swedish midwifery students feel confident in dealing with the most common procedures during normal pregnancy, childbirth, and postpartum and newborn care. However, they do not feel fully confident in cases in which there are deviations from the normal procedures and obstetric emergencies. When comparing groups of midwifery students, the younger group of midwifery students felt more confident in general compared to the older group. Students at a university with a medical faculty were also more confident than the students at a university without a medical faculty.In study II, focus group discussions were held with 14 midwives emphasizing the way in which midwives reflect on learning and the development of competence and confidence. Content analysis was used to analyze the focus group discussions. Four categories were identified as a result of study II: 1.) feelings of professional safety evolve over time; 2.) personal qualities affect professional development; 3.) methods for knowledge and competence expansion; and 4.) competence as developing and demanding. The conclusion of this thesis is that more practical and clinical training during education is desirable. Midwifery students need to have access and the opportunity to practice obstetrical emergencies within a team of obstetricians and pediatricians. Learning takes time, and one improvement is to extend midwifery education to include and increase in clinical training. This would strengthen the students theoretical, scientific, and clinical confidence. Clinical midwives claim that it takes time to feel confident and that there is a need to develop professionalism.
|
|
| 8. |
- Bäck, Lena, 1962-, et al.
(författare)
-
Professional confidence among Swedish final year midwifery students - A cross-sectional study
- 2017
-
Ingår i: Sexual & Reproductive HealthCare. - : ELSEVIER IRELAND LTD. - 1877-5756 .- 1877-5764. ; 14, s. 69-78
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Previous international studies have shown that midwifery students do not feel confident in many areas where they are supposed to practice independently. The knowledge about Swedish midwifery students' confidence is fairly under investigated. The purpose of the present study was to explore final years' midwifery students' professional confidence in basic midwifery skills according to ICM competencies and associated factors.Methods: A cross-sectional survey where all midwifery programs in Sweden were invited to participate. Data was collected by a questionnaire that measured midwifery students self-reported assessment of confidence against four selected domains of ICM competencies; antenatal, intrapartum, postpartum and new-born care.Result: The main findings of this study showed that Swedish midwifery students were confident in managing normal pregnancy, labour and birth. Midwifery students at a school with a medical faculty were more confident in handling obstetric emergency situations. Some background variables were also associated with confidence.Conclusion: This study highlighted some midwifery skills that needs further training and reflection. More training and developing confidence in complicated and emergency situations are needed. There seem to be a need of midwifery education reforms if we believe that high levels of confidence at the time of graduation is equal to competent and skilled midwives in the future.
|
|
| 9. |
- Gospic, Katarina, et al.
(författare)
-
Altruism costs-the cheap signal from amygdala
- 2014
-
Ingår i: Social Cognitive & Affective Neuroscience. - : Oxford University Press (OUP). - 1749-5016 .- 1749-5024. ; 9:9, s. 1325-1332
-
Tidskriftsartikel (refereegranskat)abstract
- When people state their willingness to pay for something, the amount usually differs from the behavior in a real purchase situation. The discrepancy between a hypothetical answer and the real act is called hypothetical bias. We investigated neural processes of hypothetical bias regarding monetary donations to public goods using fMRI with the hypothesis that amygdala codes for real costs. Real decisions activated amygdala more than hypothetical decisions. This was observed for both accepted and rejected proposals. The more the subjects accepted real donation proposals the greater was the activity in rostral anterior cingulate cortex-a region known to control amygdala but also neural processing of the cost-benefit difference. The presentation of a charitable donation goal evoked an insula activity that predicted the later decision to donate. In conclusion, we have identified the neural mechanisms underlying real donation behavior, compatible with theories on hypothetical bias. Our findings imply that the emotional system has an important role in real decision making as it signals what kind of immediate cost and reward an outcome is associated with.
|
|
| 10. |
|
|
